Doctor Roger Nicole goes on to state:

4. Calvin, they urge, asserts with Scripture that some for whom Christ died may perish (Rom 14:15; 1 Cor 8:11) or will perish (Heb 10:29; 2 Pet 2:1). These texts, perhaps more than any others in Scripture, give the advocate of definite atonement reason to pause and ponder. And Calvin does not, either in his commentaries or in the Institutes, provide any explanation of their relationship to the extent of the atonement.

To this we reply that in the context of the problem of weaker brothers, Paul affirms that they will not perish but God will make them to stand (Rom 14:4). Thus Paul’s statements do not so much represent an expression of doubt as to God’s perseverance with his own for whom Christ died, as a castigation (punishment in order to correct) of the selfishness of so-called “strong” Christians who would give priority to their own exercise of Christian liberty over the spiritual eternal interests of their weaker brothers.

The warnings of Hebrews and 2 Peter, on the other hand, do relate to people who will ultimately be lost. They do not support universal atonement, since the grounds of condemnation are the special privileges enjoyed by these apostates including “being sanctified by the blood of the covenant” and “being bought by the Master.” There is no way in which these benefits can in these verses be extended to the universality of mankind. If these apostates (one who has abandoned one's religious faith) are thought to have been regenerate at any time, however, it would appear that the scope of the atonement exceeds the scope of ultimate salvation. This would also raise a difficulty with the doctrine of perseverance. The solution may be found in viewing the description of Hebrews and 2 Peter as expressing what the apostates at one time professed to have rather than what they had in fact.

This is in any case what Calvin has opted for, as is apparent when he calls the offenders of Heb 10:29 “hypocrites…usurping (to take over or occupy without right) a place among the faithful.” This is confirmed by his treatment of Heb 6:4–6 and 10:29 in the Institutes. Calvin’s silence on the relationship of these four texts to the extent of the atonement should not, in all fairness, be construed as an endorsement of universal atonement, not any more than his silence in his commentaries on the relation of these texts to the doctrine of perseverance provides a substantial basis for affirming that Calvin did not believe in perseverance. Other passages prove beyond dispute that he did believe in it!